Method and an apparatus for removing fine-grained particles from a gaseous stream

Abstract

Method and apparatuses are disclosed for removing fine-grained particles from a gaseous sample stream from fluidized catalytic cracking regeneration unit. In one method, the fine-grained particles are wetted with condensate in a sampling system, then the wetted fine-grained particles are separated from the gaseous stream in a wetted packed column in the sampling system. The separated gaseous sample stream is cooled to remove condensible gases then is reheated. The separated fine-grained particles are kept wetted in the sampling system to prevent fouling of the sampling system, then stream is used as a motive force to return the wetted fine-grained particles to the fluidized catalytic cracking regeneration unit. The stream also is used as a drying agent to at least partially dry the wetted fine-grained particles outside of the sampling system and as a dilution agent to help prevent corrosion.

What is claimed is: 
     
       1. A method for removing fine-grained particles from a gaseous sample stream from a fluidized catalytic cracking regeneration unit comprising: (a) wetting said fine-grained particles in a sampling system,   (b) separating said wetted fine-grained particles from said gaseous stream in said sampling system,   (c) cooling said separated gaseous sample stream to remove condensible gases,   (d) keeping said wetted fine-grained particles wetted in said sampling system to prevent fouling of said sampling system, and   (e) returning said wetted fine-grained particles to said fluidized catalytic cracking regeneration unit.   
     
     
       2. A method according to claim 1 wherein a fluid provides motive force to return said wetted fine-grained particles to said fluidized catalytic cracking regeneration unit. 
     
     
       3. A method according to claim 2 wherein said fluid is a heated gas. 
     
     
       4. A method according to claim 3 wherein said heated gas at least partially dries said wetted fine-grained particles outside of said sampling system. 
     
     
       5. A method according to claim 3 wherein said heated gas is steam. 
     
     
       6. A method for removing fine-grained particles from a gaseous sample stream from fluidized catalytic cracking regeneration unit comprising: (a) wetting said fine-grained particles in a sampling system with condensate,   (b) separating said wetted fine-grained particles from said gaseous stream in a wetted packed column in said sampling system,   (c) cooling said separated gaseous sample stream to remove condensible gases,   (d) heating said cooled gaseous sample stream,   (e) keeping said wetted fine-grained particles wetted in said sampling system to prevent fouling of said sampling system,   (f) using steam as a motive force to return said wetted fine-grained particles to said fluidized catalytic cracking regeneration unit,   (g) using steam as a drying agent to at least partially dry said wetted fine-grained particles outside of said sampling system, and   (h) using steam as a dilution agent to help prevent corrosion.   
     
     
       7. An apparatus for producing a gaseous sample stream from a fluidized catalytic cracking regeneration unit comprising: (a) a means for sampling, from said fluidized catalytic cracking regeneration unit, a gaseous sample stream containing fine-grained particles;   (b) a means for wetting said fine-grained particles, wherein the means for wetting said fine-grained particles is adjacent to, and downstream from, the means for sampling a gaseous sample stream;   (c) a means for separating said wetted fine-grained particles from said gaseous stream, wherein the means for separating said wetted fine-grained particles from said gaseous stream is adjacent to, and downstream from, the means for wetting said fine-grained particles;   (d) a means for keeping said wetted fine-grained particles wetted in the apparatus to prevent fouling of the apparatus, wherein the means for keeping said wetted fine-grained particles wetted in the apparatus to prevent fouling of the apparatus is adjacent to, and downstream from, the means for separating said wetted fine-grained particles from said gaseous stream;   (e) a means for cooling said separated gaseous sample stream to remove condensible gases, wherein the means for cooling said separated gaseous sample stream to remove condensible gases is adjacent to, and downstream from, the means for keeping said wetted fine-grained particles wetted in the apparatus to prevent fouling of the apparatus;   (f) a means for heating said cooled gaseous sample stream, wherein the means for heating said cooled gaseous sample stream is adjacent to and downstream from the means for cooling said separated gaseous sample stream to remove condensible gases; and   (g) a means for returning said wetted fine-grained particles to said fluidized catalytic cracking regeneration unit, wherein the means for returning said wetted fine-grained particles to said fluidized catalytic cracking regeneration unit is adjacent to, and downstream from, the means for wetting said fine-grained particles.